1. Field of the Invention
The present invention relates generally to vaporizing type liquid fuel combustion devices and more particularly to compact liquid fueled heating devices.
2. Description of the Prior Art
In general, pot or core type liquid fuel combustion apparatuses which directly burn a liquid fuel have disadvantages in that they form soot, are noisey and produce unstable combustion. On the other hand, the vaporizing type combustion apparatuses wherein a liquid fuel (e.g. kerosene) is vaporized in a vaporizer and mixed with air for combustion and the mixed combustible gas is injected into a combustion chamber, have complicated structures, but not the other mentioned disadvantages. Accordingly, the latter have been used for large size hot air heating apparatuses such as boilers and the like.
Vaporizing type liquid fuel combustion apparatuses have equipment for forcibly feeding a liquid fuel with an electric pump to a vaporizer. Accordingly, it has been difficult to maintain relatively low heating coefficients such as 8000 - 2000 Kcal/hour, and the vaporizing type liquid fuel combustion apparatuses have not been used in practice for compact hot air heating apparatuses used in small rooms which should have relatively low heating coeffcients. For example, for a heating coefficient of about 4000 Kcal/hour using kerosene as the fuel having a calorific value of 8000 Kcal/liter the required quantity of the liquid fuel to be delivered by an electric pump is as follows: EQU 500 cc/hour =8.3 cc/minute = 0.15 cc/second.
In order to forcibly feed this small amount of the liquid fuel with a capacitive reciprocating pump driven by applying a half-wave recitifed 50 cycle commercial AC voltage, 0.15 cc of the liquid fuel is fed by 50 strokes and accordingly only 0.003 cc of the liquid fuel is fed by one cycle of the plunger. It has been hard to commercialize an electric pump having such a remarkably low feed rate and yet which has a simple structure and low cost from the viewpoint of mechanical structure.